/*
 * fsm.h - {Link, IP} Control Protocol Finite State Machine definitions.
 *
 * Copyright (c) 1984-2000 Carnegie Mellon University. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The name "Carnegie Mellon University" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For permission or any legal
 *    details, please contact
 *      Office of Technology Transfer
 *      Carnegie Mellon University
 *      5000 Forbes Avenue
 *      Pittsburgh, PA  15213-3890
 *      (412) 268-4387, fax: (412) 268-7395
 *      tech-transfer@andrew.cmu.edu
 *
 * 4. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by Computing Services
 *     at Carnegie Mellon University (http://www.cmu.edu/computing/)."
 *
 * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
 * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * $Id: fsm.h,v 1.10 2004/11/13 02:28:15 paulus Exp $
 */

#include "netif/ppp/ppp_opts.h"
#if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */

#ifndef FSM_H
#define FSM_H

#include "ppp.h"

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Packet header = Code, id, length.
 */
#define HEADERLEN 4

/*
 *  CP (LCP, IPCP, etc.) codes.
 */
#define CONFREQ 1 /* Configuration Request */
#define CONFACK 2 /* Configuration Ack */
#define CONFNAK 3 /* Configuration Nak */
#define CONFREJ 4 /* Configuration Reject */
#define TERMREQ 5 /* Termination Request */
#define TERMACK 6 /* Termination Ack */
#define CODEREJ 7 /* Code Reject */

/*
 * Each FSM is described by an fsm structure and fsm callbacks.
 */
typedef struct fsm {
	ppp_pcb *pcb;                          /* PPP Interface */
	const struct fsm_callbacks *callbacks; /* Callback routines */
	const char *term_reason;               /* Reason for closing protocol */
	u8_t seen_ack;                         /* Have received valid Ack/Nak/Rej to Req */
	/* -- This is our only flag, we might use u_int :1 if we have more flags */
	u16_t protocol;       /* Data Link Layer Protocol field value */
	u8_t state;           /* State */
	u8_t flags;           /* Contains option bits */
	u8_t id;              /* Current id */
	u8_t reqid;           /* Current request id */
	u8_t retransmits;     /* Number of retransmissions left */
	u8_t nakloops;        /* Number of nak loops since last ack */
	u8_t rnakloops;       /* Number of naks received */
	u8_t maxnakloops;     /* Maximum number of nak loops tolerated
	             (necessary because IPCP require a custom large max nak loops value) */
	u8_t term_reason_len; /* Length of term_reason */
} fsm;

typedef struct fsm_callbacks {
	void(*resetci) /* Reset our Configuration Information */
	    (fsm *);
	int(*cilen) /* Length of our Configuration Information */
	    (fsm *);
	void(*addci) /* Add our Configuration Information */
	    (fsm *, u_char *, int *);
	int(*ackci) /* ACK our Configuration Information */
	    (fsm *, u_char *, int);
	int(*nakci) /* NAK our Configuration Information */
	    (fsm *, u_char *, int, int);
	int(*rejci) /* Reject our Configuration Information */
	    (fsm *, u_char *, int);
	int(*reqci) /* Request peer's Configuration Information */
	    (fsm *, u_char *, int *, int);
	void(*up) /* Called when fsm reaches PPP_FSM_OPENED state */
	    (fsm *);
	void(*down) /* Called when fsm leaves PPP_FSM_OPENED state */
	    (fsm *);
	void(*starting) /* Called when we want the lower layer */
	    (fsm *);
	void(*finished) /* Called when we don't want the lower layer */
	    (fsm *);
	void(*protreject) /* Called when Protocol-Reject received */
	    (int);
	void(*retransmit) /* Retransmission is necessary */
	    (fsm *);
	int(*extcode) /* Called when unknown code received */
	    (fsm *, int, int, u_char *, int);
	const char *proto_name; /* String name for protocol (for messages) */
} fsm_callbacks;

/*
 * Link states.
 */
#define PPP_FSM_INITIAL 0  /* Down, hasn't been opened */
#define PPP_FSM_STARTING 1 /* Down, been opened */
#define PPP_FSM_CLOSED 2   /* Up, hasn't been opened */
#define PPP_FSM_STOPPED 3  /* Open, waiting for down event */
#define PPP_FSM_CLOSING 4  /* Terminating the connection, not open */
#define PPP_FSM_STOPPING 5 /* Terminating, but open */
#define PPP_FSM_REQSENT 6  /* We've sent a Config Request */
#define PPP_FSM_ACKRCVD 7  /* We've received a Config Ack */
#define PPP_FSM_ACKSENT 8  /* We've sent a Config Ack */
#define PPP_FSM_OPENED 9   /* Connection available */

/*
 * Flags - indicate options controlling FSM operation
 */
#define OPT_PASSIVE 1 /* Don't die if we don't get a response */
#define OPT_RESTART 2 /* Treat 2nd OPEN as DOWN, UP */
#define OPT_SILENT 4  /* Wait for peer to speak first */

/*
 * Timeouts.
 */
#if 0                     /* moved to ppp_opts.h */
#define DEFTIMEOUT 3      /* Timeout time in seconds */
#define DEFMAXTERMREQS 2  /* Maximum Terminate-Request transmissions */
#define DEFMAXCONFREQS 10 /* Maximum Configure-Request transmissions */
#define DEFMAXNAKLOOPS 5  /* Maximum number of nak loops */
#endif                    /* moved to ppp_opts.h */

/*
 * Prototypes
 */
void fsm_init(fsm *f);
void fsm_lowerup(fsm *f);
void fsm_lowerdown(fsm *f);
void fsm_open(fsm *f);
void fsm_close(fsm *f, const char *reason);
void fsm_input(fsm *f, u_char *inpacket, int l);
void fsm_protreject(fsm *f);
void fsm_sdata(fsm *f, u_char code, u_char id, const u_char *data, int datalen);

#ifdef __cplusplus
}
#endif

#endif /* FSM_H */
#endif /* PPP_SUPPORT */
